Refrigerator



3 Sheets-Sheet l E. R. SWANSON l REFRIGERATOR Filed Feb. 2, 1942 'yl'.f

Get. 19, 1943.

Oct. 19, 1943. E.l R. swANsoN 2,332,027

REFRIGERATOR Filed Feb. 2, 1942 5 Sheets-Sheet 3 l'amyb.

pmta oa. 19, 1943 2,332,127

UNITED STATES PATENT OFFICE REFRIGERATUR Earl It. Swanson, Chicago, Ill., assignor to Standard Railway Devices Company, Chicago, lll., a corporation of Delaware Application February 2, 1942, Serial No. 429,234 A Claims. (Ci. S75-91.5)

This invention relates to refrigerators, particularly to refrigerators in which a secondary liquid refrigerant is cooled by the primary refrigerant and circulates in a conduit disposed within the interior of the refrigerator. I have shown my invention embodied in a railway refrigerator car but it is understood that I do not wish to limit it to such an application.

The drawings illustrate my invention as a part of a modified overhead bunker refrigerator car wherein the refrigerating means is-disposed immediately below the roof and flues associated with the side walls of the car conduct air cooled by the refrigerating means to the space under extend lengthwise of ruption. l

A further object is to embody in a car of the type hereinabove described, means for directing a flow of air from outside the car to inside the car so as to ventilate the contents ofthe car.

Other objects and advantages of my invention will be apparent from the following detailed description by referring to the accompanying drawings.

In the drawings:

Fig. l is a transverse section through a refrigerator car embodying my invention.

Fig. 2 is a plan section through the car as indithe car without interthe floor rack. The air then filters upwardly cated by line 2-2 0f Fig. 1. through the rack, through the lading compart- Fig. 3 is a longitudinal section through the car ment, thereby cooling the lading, and finally re- 0n line 3-3 of Fig. 2. turns to the refrigerating means from where the Fig. 4 iS a Partial transverse SeCtiOn 0n line cycle is repeated. 4-4 0f Fg- 3 Secondary refrigerant systems are well known Fig- 5 is a Partial transverse Section through in the refrigeration art and embody a receptacle for a refrigerant which is commonly solid carbon dioxide (dry ice) on account of the extremely low temperature of such refrigerant. The receptacle is at least partially surrounded by a jacket substantially filled with secondary fluid refrigerant and a conduit disposed in the path of the circulating air within the refrigerator has its ends communicating with the jacket, one end of the conduit being at a higher elevation thanv the other end. The secondary refrigerant flows through the conduit due to the fact that the colder, and therefore denser, liquid in the jacket flows into the low end of the conduit and, by convective circulation, the warmer liquid flows out of the high end of the conduit and into the upper part of the jacket. The circulating air is cooled by contact with the cold conduit.

An object of my invention is to embody such a secondary refrigerant systemy in an overhead bunker type of refrigerator car in such a way as to provide stage cooling of the circulating air. The circulating air is directed-into contact rst with the relatively warm part of the conduit which leads the secondary refrigerant to the jacket and then in contact with the relatively cold part of the conduit which leads the secondary refrigerant from the jacket. I illustrate several methods of accomplishing this object as will be pointed out in detail.

Another object is to provide a cupola upstanding from the roof of the car and to dispose the refrigerant receptacle within the cupola so that the conduits for the secondary refrigerant may the upper part of a car showing a modified form of my invention.

Fig. 6 is a section on line 6-6 of Fig. 5.

The general parts of the refrigerator cars shown in the drawings are the insulated roof 2, side walls 3, end wall 5, floor 6, foraminous floor rack 8, the space 9 between the floor 6 and the rack 8 and the flues Il associated with the side walls 3 and communicating at their lower ends with the space 9. In the modification shown in Figs. l to 4, the refrigerant receptacle I2 is disposed immediately below the roof 2 and extends ybetween opposite side walls 3 of the car adjacent an end wall 5. A similar receptacle is preferably positioned adjacent the opposite end wall. It is understood that the receptacle could be positioned adjacent the longitudinal center of the car, at the quarter length, or in any other desired position. One or more hatches I4 are provided in the roof 2 for loading refrigerant into the receptacle i2. The refrigerant illustrated is solid carbon dioxide, which is known as dry ice and which is furnished commercially in the approximately 10" cubes illustrated in the drawings. Any other suitable refrigerant may be used in place of the dry ice illustrated.

A hollow jacket i9 filled with a secondary fluid refrigerant is disposed around the sides and under the bottom of the refrigerant receptacle I2 and the receptacle and Jacket are insulated (20) from the lading compartment 22 of the car. The upperpart of the car not occupied by the receptacle i2 is used to provide air cooling chambers 23 preferably extending longitudinally of the car adjacent each of the side walls 3. 'I'he chambers 23 are formed by substantially horizontal partitions 25 aligned with the lower side of the insulation 2B and upright walls 26 spaced apart to form a duct 28 leading upwardly from the lading compartment 22 between the air cooling chambers 23 on opposite sides of the car. The upper edges 29 of the upright walls 26 are spaced below the roof 2 so that air may ow from the duct 28 into both chambers 23.

Conduits 33 in which the secondary fluid refrigerant circulates are disposed within the air cooling chambers 2? and may be formed in any shape suitable for the purpose. Two forms of conduit are illustrated on opposite sides of the car as will be apparent from Figures l to 3. At the left side of Fig. 1, there are three U shaped conduits 34 the ends of each of which communicate with the jacket I9, the low sides 36 of the conduits 33 communicating with the lower part of the jacket I9 and being disposed adjacent the side nues l I and the high sides 3l communicating with the upper part of the jacket i9 and being disposed adjacent the center duct 2S. As the air within the air cooling chambers 23 absorbs heat from the uid within the conduits 3d, the fluid flows upwardly through the conduits 3ft and downwardly within the jacket I9 on the principle of convective circulation. As the air within the cooling chambers 23 absorbs heat from the secondary refrigerant, the air is cooled and falls, due to its greater density, through the side wall fiues I I into the space 9 below the floor rack 8, upwardly through the lading compartment 22 into the duct 28 and thence into the cooling chambers 23. It is evident that the secondary refrigerant in the low sides 36 of the conduits 34 which lead refrigerant from the jacket is colder than that in the high sides 31 of the conduits. The circulating air, upon entering the cooling Chambers 23, contacts the high sides 3'I of the conduits 34 and is partially cooled; it then contacts the lower sides 36 of the conduits 34 and is further cooled in a stage cooling process which derives the greatest efciency from the refrigerant.

The right side of Fig. 1 illustrates a modified form of conduit 33 formed of a continuous pipe 4|I having one end 4I communicating with the lower part of the jacket I9 adjacent the side wall flue II; the pipe 40 is inclined upwardly therefrom and the opposite end 43 of the pipe 40 communicates with the upper part of the jacket I9 adjacent the duct 28. The convective flow of secondary refrigerant is similarly from the jacket I9 into the lower end 4| of the conduit 40. upwardly through the conduit, into the upper part of the jacket and downwardly through the jacket. 'I'he refrigerant within the upper part of the conduit 4I) is thus warmer than that within the lower part of the conduit. It is evidentin this modification that the air entering the chamber 23 is directed into contact first with the warmest part of the conduit 40 and then into contact with successively cooler parts until it contacts .the coldest part immediately prior to entering the upper end of the side wall flue I I.

In order to increase heat transfer between the conduit and the circulating air, it may be desirable to provide concentric fins 4E upon the conduits 33 as shown in Figs. 1 to 3. It is evident that the planes of the fins 46 are parallel with the direction of air flow through the chamber 23 and therefore form no obstruction to the flow of such air.

Figs. 5 and 6 illustrate a modiied form of the aesaoay invention embodied in a car having a structure similar to that shown in Figs. i to 4. The refrigerant receptacle 50, jacket 5I and insulation 53 therefor are supported on the upper sides of the inner side plates 5d and certain inner frame members 56 are made higher so as to extend over the top of the receptacle 5B. Insulation 5i is provided around the receptacle 50 and the insulation 5l is preferably covered with a metallic sheet 59 attached to the outer side plates 60 to form a cupola G2.

The air cooling chambers 65 are formed of partitions 66 and upright walls 68 as heretofore described and extend continuously between opposite end walls 5 of the car. The conduits 69 may be formed in any convenient shape, continuous pipes being illustrated. The low ends ll of such pipes are disposed near the side wall iiues II and communicate (El) with the lower part of the jacket 5I while the upper ends 'i2 are disposed adjacent the center duct 28 and communicate (13) with the upper part of the jacket 5|. The convective flow of secondary refrigerant is upwardly through the conduits GS and the circulatin-g air, upon entering the air cooling chambers 65, contacts rst the warmest parts of the conduits 69 and immediately prior to entering the side wall flues II contacts the coldest parts of the conduits.

The cupola 62 is preferably provided with one or more openings 'I5 in an end wall thereof and a passage 'I6 leading from the opening I5 downwardly to the air cooling chambers 65. The opening 'I5 is provided with a door I8 having an adjustable latching means I9 so that air for ventilating purposes may flow through the opening I5 into the air cooling Chambers 65 and thence into the lading compartment 22 through either the side wall fiues I I or center duct 28.

The accompanying drawings illustrate the preferred form of the invention, though it is to be understood that the invention is not 'limited to the exact details of construction shown and described, as it is obvious that various modifications thereof, within the scope of the claims, will occur to persons skilled in the art.

I claim:

1. In combination with the walls, roof and floor of a refrigerator car, a foraminous rack for supporting a lading and providing a space between the floor and the lading compartment, flues associated with opposite walls of said car communi-A cating at their lower ends with said space, means forming an air cooling chamber below said roof communicating with the upper part of at leasil one of said flues and a duct remote from the flues communicating at its lower end with said compartment and at its upper end with said chamber at a higher elevation than the flues, a cupola upstanding from said roof, a refrigerant receptacle in said cupola, a jacket thermo-conductively associated with said receptacle and containing a secondary uid refrigerant, conduit means within said chamber communicatively attached to said jacket and arranged for convective flow of secondary refrigerant through said conduit means, the parts of said conduit means which conduct refrigerant from said jacket being disposed adjacent said flues and the parts which conduct refrigerant to said jacket being disposed adjacent said duct, said cupola including a passage for flow of Ventilating air to the interior of the car.

2. In combination with the walls, roof and iloor of a refrigerator car, a foraminous rack for supporting a lading and providing a space between the floor and the lading compartment,

ilues associated with vopposite walls of s'aid carwith said chamber at a higher elevation than the iues, a cupola upstanding from said roof, a refrigerant receptacle in said cupola, a jacket thermo-conductively associated with said receptacle and containing a secondary uidy refrigerant, conduit means within said chamber communicatively attached to said jacket and arranged for convective ilow of secondary refrigerant through said conduit means, the parts of said conduit means which conduit refrigerant from said jacket being disposed adjacent said nues and the parts which conduct refrigerant to said jacket being disposed adjacent said duct, said conduit means being substantially lminterrunted from end to end of the car.

3. A .refrigerating means for a refrigerator having an air cooling chamber and a lading compartment therebelow, said chamber being closed except for an air inlet between said chamber and compartment at a higher elevation than an air outlet between said chamber and compartment for convective air circulation therethrough, said refrigerating means comprising a primary refrigerant receptacle, a jacket thermo-conductiveLv associated with said receptacle adapted to contain a secondary iiuid refrigerant, lconduct means arranged within said chamber' and connected to said jacket for convective iiow of said secondary refrigerant therethrough, said conduit means being substantially in a plane inclined downwardly from said air inlet to said air outlet.

4. A refrigerating means for a refrigerator having an air cooling chamber and a lading compartment therebelow, said chamber being closed except for an air inlet between said chamber and compartment at a higher elevation than an air outlet between said chamber and compartment for convective air circulation there-l through, said refrigerating means comprising a primary refrigerant receptacle above said cooling chamber, a jacket thermo-conductively associated with said receptacle adapted to contain a secondary uid refrigerant, conduit means ar' ranged within said chamber partially below said receptacle and connected to said jacket for convective ow of said secondary refrigerant therethrough. l

5. A refrigerating means for a refrigerator having an air cooling chamber and a lading compartment therebelow, said chamber being closed except for an air inlet between said chamber and compariment at a higher elevation than an air outlet between said chamber and compartment for convective air circulation therethrough, said refrigerating means comprising a primary refrigerant receptacle, a jacket thermoconductively associated with said receptacle adapted to contain a secondary iiuid refrigerant,

a plurality of conduits extending laterally from said receptacle and connected to said jacket for convective flow of said secondary refrigerant therethrough, approximately half of each of said conduits being adjacent said air inlet and approximately the other half of each of said conduits being adjacent said air outlet.

EARL R. SWANSON. 

